The present invention relates to the field of communications in general and more particularly to broadband access such as digital subscriber line, cable or satellite network communications.
Broadband access terminals, such as cable modems, digital subscriber line (DSL) modems and satellite modems, typically provide high-speed, always-on, connections to the Internet using Transmission Control Protocol/Internet Protocol (TCP/IP). In order to facilitate rapid deployment of broadband services, it may be beneficial that access terminals located at a customer's premises be capable of providing diagnostic information to a user. Such diagnostic information may be provided, for example, by an embedded web server in the broadband access terminal which may be accessed by a web browser or the like using, for example, the hypertext transport protocol (HTTP) and TCP/IP.
In certain conventional broadband access terminals (BATs), a web server, dynamic host configuration protocol (DHCP) server, and domain name server (DNS) hi-jack capabilities are embedded in the BAT. The embedded DHCP server, typically, assigns a private IP address to a user's equipment, such as a personal computer or the like, when the wide area network (WAN) link is unavailable. The DNS hi-jack function intercepts DNS queries for a predefined universal resource locator (URL) and responds with the embedded web server's IP address. Such BATs typically allow access to diagnostic web pages provided by the embedded web server when the WAN link is available immediately after the BAT is powered up or when the WAN link is not available when the BAT is powered up such that, when the user's equipment is later powered up, it will obtain an IP address from the embedded DHCP server.
Unfortunately, conventional BATs, as described above, may fail to provide access to the embedded web server to a user's terminal if, after some time of normal operation, the WAN link becomes unavailable. In such a case, the user's equipment has, typically, been assigned a global routable IP address by a DHCP server of a service provider which is accessible over the WAN link. The global routable IP address, typically, has a relatively long lease (e.g. 1 day to 1 week). When a user tries to access the embedded web server of the BAT, the embedded web server may be unavailable because an entry corresponding to the embedded web server in an address resolution protocol (ARP) cache in the user's equipment has expired. Entries in an ARP cache typically expire in a relatively short period of time (e.g. 10 minutes). The web server may be accessed if the user reboots the user's equipment or reconfigures the equipment, but such an operation may be unsuitable, for example, because a typical user may be non-technical or because potentially important diagnostic information may be lost in the reboot process.